SPST switch symbol
Also called Single pole single throw, On/off switch, Toggle switch, One-way switch
A single pole, single throw switch: one circuit, opened or closed. Drawn open, as it sits in its normal position.
What the SPST switch symbol means
A single pole, single throw switch: one circuit, opened or closed. Drawn open, as it sits in its normal position.
ANSI and IEC symbols
Where you see it
On/off switches, light switches and isolating switches in control circuits.
What is written next to it
On a schematic, the SPST switch usually carries its designator, such as S1, and sometimes the current rating.
Related symbols
Frequently asked questions
What does the SPST switch symbol look like?
On ANSI drawings: A hinged blade, drawn open, between two terminals. In IEC 60617: The same open blade, usually without the terminal circles.
Is the SPST switch symbol the same in IEC and ANSI?
Yes, it is drawn the same way in most legends.
Where is a SPST switch used?
On/off switches, light switches and isolating switches in control circuits.
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